The present invention relates to a bobbin hanger for use in the textile industry and, more specifically, to a bobbin hanger for holding a yarn package or a roving package on a textile machine or for conveying a yarn package, a roving package or an empty bobbin.
Various bobbin hangers are used in the textile industry. Shown in FIG. 10 is a typical currently and widely used bobbin hanger capable of smooth rotation and slight swing. This bobbin hanger has a bobbin hanging tube 1 having an expanded section 1a having a larger diameter and a reduced section 1b having a smaller diameter, and joined to a tubular holding member 2. A bobbin B is fitted on the reduced section 1b. As shown in FIG. 11, longitudinal grooves 1c (only one of them is shown in FIG. 11) are formed diametrically in the reduced section 1b. An opening 1d is formed at the upper end of each groove 1c so as to connect with a longitudinal, bottomed square hole 1e formed coaxially in the central portion of tee reduced section 1b. Grooves 1q are formed, respectively, in the opposite surfaces of the square hole 1e so as to correspond to the grooves 1c respectively. Longitudinal slots 1i are formed diametrically at an angular distance of 90.degree. from the grooves 1c in the lower end of the reduced section 1b so as to connect with the square hole 1e to receive retractable bobbin holding fingers 6 therein. A weight 3 having inner projections 3a is put on the reduced section 1b with the inner projections 3a received, respectively, in the grooves 1c for axial movement along the reduced section 1b. A pin 1h is fitted in a hole 1p penetrating the lower ends of the bottom walls of the grooves 1c so that the opposite ends thereof project into the grooves 1c to prevent the weight 3 from falling off the reduced section 1b. A sliding member 4 shown in FIG. 12 is fitted slidably in the square hole 1e of the reduced section 1b. The bobbin holding fingers 6 are joined pivotally to the lower end of the sliding member 4 with a pin 6a. A retaining member 5 is supported pivotally on the upper part of the sliding member 4 with a pin 5d. The retaining member 5 has a square ratchet 5a and a base block 5b formed integrally with the square ratchet 5a. Projections 5c are formed, respectively, on a pair of opposite sides of the base block 5b. Grooves 4a are formed diametrically in the upper end of the sliding member 4. Sliding member 4 is provided with flanges 4b in the upper portion thereof. The flanges 4b rest on the upper end 1f (FIG. 11) of the reduced section 1b to limit the downward movement of the sliding member 4. Splines 4d extending downward from the flanges 4b engage the grooves 1q formed in the square hole le and project through the openings 1d into the grooves 1c so as to engage the projections 3a of the weight 3, respectively. A ratchet operating member 7 is formed by bending a single spring strip and has an operating leg 7a, a head 7b and a stopping lug 7c. In assembling the bobbin hanger, the ratchet operating member 7 is put in the grooves 4a of the sliding member 4, the bobbin holding fingers 6 are retracted into the sliding member 4, the sliding member 4 is inserted in the square hole 1e of the bobbin hanging tube 1, a compression spring 8 is placed on the flanges 4b, a holding plate 9 is placed on top of the compression spring 8, and then a pin 2a is inserted in through holes 1g formed in the wall of the expanded section 1a of the bobbin hanging tube 1, through holes 2b formed in the wall of the holding member 2 and a through hole 9a formed in the holding plate 9 to join together the bobbin holding tube 1 and the holding member 2 as shown in FIG. 13. When the bobbin hanger is thus assembled, the stopping lug 7c of the ratchet operating member 7 rests on the upper end 1f of the reduced section 1b, and the head 7b of the ratchet operating member 7 is received in a recess 9b (FIG. 13) formed in the lower surface f the holding plate 9. When placed substantially in a horizontal position, the projections 5c of the base block 5b engage the upper end lf to retain the sliding member 4 at an upper position as shown in FIG. 13. In this state, the bobbin holding fingers 6 are retracted into the reduced section 1b of the bobbin hanging tube 1, and the weight 3 rests on the pin 1h.
In hanging a bobbin B on the bobbin hanger, the weight 3 is pushed up by the bobbin B, while the projections 3a of the weight 3 engage the lower ends of the splines 4d of the sliding member 4 projecting into the openings 1d to push up the sliding member 4 to an uppermost position against the resilience of the compression spring 8 as shown in FIG. 14. Consequently, the tooth of the ratchet 5a of the retaining member 5 engages the lower end of the operating leg 7a of the ratchet operating member 7, and thereby the retaining member 5 is turned through an angle of 90.degree. and the projections 5c are placed in a vertical position as shown in FIG. 14 as the sliding member 4 is moved upward. Then, an upward force applied to the bobbin B is removed. Consequently, as shown in FIG. 15, the bobbin B drops together with the weight 3 to a hanging position, where the retaining member 5 is received in the square hole le, the flanges 4b of the sliding member 4 rest on the upper end 1f of the reduced section 1b, and the bobbin holding fingers 6 are caused to swing outward by the pin 1h and engage the stepped par B.sub.1 of the bobbin B to hold the bobbin B on the bobbin hanger.
In removing the bobbin B from the bobbin hanger, the bobbin B is pushed up again to move the sliding member 4 to the uppermost position, whereby the retaining member 5 is turned through an angle of 90.degree. and the bobbin holding fingers 6 are retracted into the bobbin hanging tube 1 to release the bobbin B.
In hanging the bobbin B on this conventional bobbin hanger, the bobbin B is put on the reduced section 1b of the bobbin hanging tube 1 and pushed up by hand together with the weight 3 to an uppermost position, where the upper end of the weight 3 is in abutment with the lower end 1r of the expanded section 1a. Thus, the bobbin hanger is designed so that the retaining member 5 pivotally supported on the sliding member 4 has been turned through an angle of 90.degree. by the operating leg 7a of the ratchet operating member 7 before the bobbin B arrives at the uppermost position where the upper end of the weight 3 is in abutment with the lower end 1r of the expanded section 1a, and an allowance C, namely, the distance between the upper end of the weight 3 and the lower end 1r of the expanded section 1a at the completion of turning of the retaining member 5 through an angle of 90.degree., is very small. Thus, the bobbin B is pushed up to the uppermost position in hanging the bobbin B on and removing the same from the bobbin hanger by hand.
Recently, bobbin changing apparatus have been introduced into spinning mills for the mechanical bobbin changing operation on spinning frames and roving frames. The bobbin changing apparatus puts bobbins on bobbin hangers and removes the same from the bobbin hangers individually or simultaneously with arms 10 (FIG. 10). When such a mechanical bobbin changing apparatus is used for mechanically putting bobbins on and removing the same from bobbin hangers, it is difficult to position bobbins in alignment with the bobbin hanging tubes of the bobbin hangers unless the bobbin hangers are disposed very accurately. Furthermore, since the stroke of the arm of the mechanical bobbin changing apparatus is fixed, the bobbin hangers must be arranged on the same level, and it is difficult to achieve mechanical bobbin changing operation satisfactorily if the bobbin hangers are arranged on different levels or the bobbin hangers are supported on an easily bendable support.
Since the lower end 1j of the reduced section 1b of the bobbin hanging tube 1 is flat as shown in FIG. 13, sometimes, the bobbin hanging tube 1 fails to enter the bore of the bobbin B smoothly. Particularly, since the result of the mechanical bobbin changing operation is not confirmed by the operator, it is possible that the bobbin is not hung on or removed from the bobbin hanger successfully or the bobbin hanger is damaged by a faulty mechanical bobbin changing operation.
When a horizontal force acts in the direction of an arrow F.sub.1 on the bobbin holding finger 6 engaging the inner stepped part B.sub.1 of the bobbin B, FIG. 15, to cause the bobbin holding finger 6 to be moved in the direction of an arrow M.sub.1 by the pin 1h engaging the inclined surface 69 of the bobbin holding finger 6 and the bobbin B falls off the bobbin hanger, which is possible to occur when the bobbin conveying apparatus is braked abruptly or started suddenly, because the downward pressure applied to the sliding member 4 by the compression spring 8 is small to facilitate bobbin hanging operation and bobbin removing operation, and the inclined surface 69 of the bobbin holding finger 6 is liable to slide upward along the pin 1h.